It’s useful to keep track of the link between a Source record and a Target record in a so called “Link table”.
Benefits of a link table:
- It’s a log of all records that have been successfully synced to the target
- It can be used to lookup the id in the target of a parent record, when adding a child
- It can be used for rollback (delete records in target)
This table can be created manually in Peliqan for each object type in the sync, and the table contains at minimum 2 columns:
- source_id
- target_id
Example link table for “Task” objects:
Table name: link_table_tasks
source_id | target_id |
1 | abc456 |
6 | def789 |
8 | ghi432 |
Pseudo-code:
GET SOURCE ROWS
FOR EACH SOURCE ROW:
CHECK IF RECORD ALREADY IN TARGET (LOOKUP IN LINK TABLE) ? IF NOT:
1. DO FIELD MAPPING
2. ADD TO TARGET
3. ADD ROW IN "LINK TABLE"Here’s the pseudo code in a bit more detail for records of type “Task”:
source_rows = dw.fetch(table) # e.g. list of "Tasks"
for row in source_rows:
source_id = row["task_id"]
if source_id not in link_table_tasks: # Task is not in target yet
# Field mapping
target_row = {
target_field = source_field,
target_field = source_field,
target_field = source_field
}
target_id = target.add(target_row)
dw.insert("link_table_tasks", source_id, target_id)